Hvordan fungere "this"?

I denne kode hvad svarer "this" så til hvis jeg i en main metode har følgende:

RoomBehavior x = new BasicRoom("kitchen", "pasta");
Explorer harpo = new Explorer("Harpo Marx", "swordfish");

kode:

public class Explorer implements PlayerBehavior {
   
    private String my_name;
    private String my_secret_word;
    private RoomBehavior where_I_am_now;
   
    public Explorer(String name, String word){
       
        my_name = name;
        my_secret_word = word;
        where_I_am_now = null;
       
      }
   
    public String speak(){
       
        return my_secret_word; }
   
   
    public void exitRoom(){
       
        if ( where_I_am_now != null )
          { where_I_am_now.exit(this);
            where_I_am_now = null;
          }
      }
   
    public boolean explore(RoomBehavior r){
       
        if ( where_I_am_now != null )
          { exitRoom(); }
     
        boolean went_inside = r.enter(this);
        if ( went_inside )
          { where_I_am_now = r; }
        return went_inside;
      }
   
    public RoomBehavior locationOf(){
       
        return where_I_am_now; }
    }